1. Field of the Invention
The present invention relates to a card connector for use in exchanging signals with an inserted card, e.g., an IC card, and more particularly, to a card connector having a detection switch for sensing that a card has been inserted in a card slot.
2. Description of the Related Art
An IC card contains an IC chip having calculation and storage functions. Information processing equipment for processing information by using this IC card as a medium, i.e., a personal computer and a digital camera, is equipped with an IC card connector having a plurality of terminals corresponding to contact patterns formed on the surface of the IC card.
An IC card connector has been known hitherto, in which a connector body is provided with a normally closed detection switch for sensing that an IC card has been inserted in a card slot (see, for example, U.S. Pat. No. 4,900,273). FIGS. 34 to 37 show the mechanism of the IC card connector. FIGS. 34 and 35 are partial side and partial plan views, respectively, showing a state before an IC card is inserted in the card slot, and FIGS. 36 and 37 are partial side and partial plan views, respectively, showing a state in which the IC card is inserted in the card slot.
As shown in these figures, a card slot 102, in which an IC card 101 (see FIG. 36) is inserted, is formed at a predetermined position of a connector body 100. Below the card slot 102, a movable terminal 103 and a fixed terminal 104 extending along the inserting direction (X-direction) of the IC card 101 are mounted to constitute a normally closed detection switch.
Before the IC card 101 is inserted in the card slot 102, the movable terminal 103 is inclined and is in elastic contact with the fixed terminal 104, and a bent leading end portion 103a thereof is placed inside the card slot 102, as shown in FIG. 34. Numeral 105 denotes a space portion for allowing pressure deformation of the movable terminal 103.
When the IC card 101 is inserted in the card slot 102, as shown in FIG. 36, the leading end portion 103a of the movable terminal 103 is pressed by the leading end portion of the IC card 101. The movable terminal 103 is thereby pressed down, and a leading end portion 103a of the fixed terminal 104 performs self-cleaning in sliding contact with the upper surface of the movable terminal 103, while the movable terminal 103 separates from the fixed terminal 104, so that the insertion of the IC card 101 is electrically detected. Furthermore, the IC card 101 is elastically held by repulsive force produced by pressure deformation of the movable terminal 103, and is kept in the inserted state. In this state, signal exchange (information processing) is carried out.
When the IC card 101 is drawn out of the card slot 102 after the completion of information processing, the movable terminal 103 returns to the state shown in FIG. 34 by its repulsive force, and makes contact again with the fixed terminal 104, whereby the ejection of the IC card 101 is detected.
In this normally closed detection switch, however, since elastic force always acts in the card ejecting direction (the direction of the arrow Y in FIG. 36) when the IC card 101 is inserted, the card 101 is liable to come out due to vibrations or the like, and it is difficult to hold it stably. For this reason, there is a problem with operation reliability in information processing.
When elastic force is reduced due to changes in the movable terminal 103 over time, the force for holding the inserted IC card 101 is also reduced, and the card is liable to come out due to even small vibrations.
Furthermore, since the detection switch is placed under the card slot 102 and is directly exposed on the side of the card slot 102, contaminants, oil, and the like which have entered with the inserted IC card 101 are scraped and collected at the contact portion of the detection switch, which may cause contact failure.